Natural disasters
Mount Ruapehu is one of the most active volcanoes in the world. If there was a big eruption, the ash and other material from the volcano could spread through the air and get into local waterways. This material could pollute the rivers and lakes and kill the plants and animals that live there.
Storms and flooding could also affect the water in local waterways. Lots of silt could be carried into the rivers and lakes. Plants and animals in the water could find it hard to breathe and hunt for food if there is a lot of silt in the water.
Human impacts
Changing waterways
One of the biggest threats to freshwater ecology is from water being changed from its natural course to provide irrigation, water supply, and energy production.
Towns and cities - urbanisation
When it rains in urban areas, the rain that runs off buildings and down the gutters is called storm water run-off. Storm water run-off can carry pollution into the local waterways.
Special effort is made when planning new towns and housing areas so that we have good water quality.
- Find out more about native fish in urban waterways and what you can do to help.
Nitrogen
Over the last fifty years, land and industrial development in the Taupō area has increased the amount of nitrogen in the water. Nitrogen makes algae grow faster, which makes the water murky. The health of Lake Taupō and its rivers, depends upon clean, clear water.
Over-fishing
Over-fishing can lead to certain animals disappearing. This affects other animals who eat them and all the animals in the food web are affected. The health of a waterway can be measured by how many different things live there.
